US2780701A

US2780701A - Electrical contacts

Info

Publication number: US2780701A
Application number: US537333A
Authority: US
Inventors: Louis J Patla
Original assignee: Individual
Current assignee: Individual
Priority date: 1950-10-10
Filing date: 1955-09-29
Publication date: 1957-02-05
Anticipated expiration: 1974-02-05

Description

Feb. 5, 1957 L. J. PATLA 2,78%,761

ELECTRICAL CONTACTS Filed Sept. 29, 1955 2 Sheets-Sheet l 1y Tm I04 li //a 24 I x T HHHIHI Felix. 195 L. J. PATLA ELECTRICAL CONTACTS Filed Sept. 29, 1955 2 Sheets-Sheet 2 IN VEN TOR. of

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BY. J r, W mww ELECTRICAL CONTACTS Louis J. Patla, Elmwood Park, Ill.

Original application October 10, 1950, Serial 159,458, now Patent No. 2,721,911, dated October 25, 1955.

Divided and this application September 29, 1955, Se- 1 rial No. 537,333

16 Claims. or. 200-166) This invention relates to a method and construction for mounting a switch contact or other electrical conductor on a supporting member, which 'may be electrically conducting, with the conductor extending through and insulated from the supporting member. The invention is particularly applicable to the mounting of contacts in a rotating switch such as that disclosed and claimed in application, Serial No. 189,458 entitled Rotary Switch and filed October 10, 1950, now Patent #2,721,911, October 25, 1955, by the same inventor, of which the present application is a division, but is not necessarily limited thereto. It is an object of the invention to provide an improved method and construction of the foregoing character. I

When the method and construction are employed in a rotating switch a large number of switch contacts may be readily mounted on a metal supporting plate and are insulated therefrom while passing through openings therein. This objective is obtained in accordance with the invention by a very simple, reliable, and economical construction.

It is another object of the invention to provide improved means for mounting a plurality of electrical condoctors on a supporting member which may be electrically conducting, the conductors extending through an opening in the supporting member and being insulated from each other and from the member.

It is another object of the invention to provide an improved method for mounting a plurality of electrical conductors on an electrically conducting plate, the conductors extending through an opening in said plate and being insulated from each other and from the plate.

It is another object of the invention to provide an improved rotating switch in which one set of contacts is mounted on an electrically conducting plate, the contacts extending through an opening in the plate and being insulated from each other and from the plate.

The invention,together with further objects and advantages thereof, will best be understood by reference to the following description taken in connection with the accompanying drawings, and its scope will be pointed out in the appended claims.

In the drawings in which like parts are designated by like reference numerals,

'alongthe line 3-3 of Fig. 1

Fig. 4 is an enlarged cross-sectional view taken along the line 4-4 of Fig. 2;

Fig. 5 is an enlarged partial cross-sectional view taken along the line 5-5 of Fig. 2;

Fig. 6 is' an enlarged partial cross-sectional view taken along the line 6-6 of Fig. 2;

Fig. 7 is an enlarged partial perspective view showing certain portions of the switch disassembled;

Fig. 8 is a partial perspective view of another embodiment of the invention; and

Fig. 9 is a partial cross-sectional view taken along the line 99 of Fig. 8.

The embodiment of the switch disclosed in the drawings is shown applied to a band switch for radio equipment such as a television receiver. More particularly, the switch is shown controlling circuits including a series of tubes 10, 11, and 12, which are mounted in

respective sockets

10a, 11a, and 12a, adjacent the switch. The switch comprises a bank of three

elements

13, 14 and '15, each of these elements controlling the circuits incorporating one of the tubes 10, 11, and 12. The three switch elements are supported by a common framework and base and operated by a common control device, all as will be explained in detail subsequently.

Each section of the switch includes a stationary member 20 which supports stationary contacts 21 by an arrangement best seen in Figs. 2, 4, and 7. The member 21 is shown as being cup-shaped and is preferably of metal in the interest of greater strength and rigidity for reasons which will subsequently become clear. The cup shaped member 20 has an opening 22 extending therethrough and, in the preferred embodiment, pairs of

slots

23, 24, and 25 extending through that member and communicating with the opening 22. A series of sheets of of

slots

23, 24 or 25, the edges of the sheets being snugly engaged by the edges of the cup-shaped member defining the slots. Preferably the edges 27 of the sheet 26 which enter the slots not only fit snugly between the longitudinal edges of the slots but also snugly engage the ends of the slots. in such case, the edges of the member 20 defining the longitudinal sides of the slots prevent movement of the sheet 26 in a direction normal to the sheet while the edges of the member 20 defining the ends of the slots prevent movement of the sheet 26 circumferentially of the cup-shaped member.

In the preferred embodiment of the invention, the sheet 26 also has a pair of cars 28 extending laterally of the edges 27 and forming shoulders 29 which engage the rear surface of the member 20. This facilitates "proper positioning of the sheets 26 during assembly and makes for a more solid construction. After the sheet 26 has been inserted in the slots the member 20 is deformed adjacent the edges of the slots. This deformation of the member 20, which may be in the form of punch or chisel marks 30, best seen in Figs. 2 and 6, displaces the metal forming the longitudinal edges of the slots inwardly against the surfaces of the sheet 26. This result is shown in Fig. 6 wherein it is seen that the metal forming the edges of the slot 25 has been driven into the sheet 26, thereby firmly locking the sheet in fixed position with respect to the cup-shaped member 20.

The stationary contacts 21 are secured to the surfaces of the sheets 26 by any suitable means, such as by the rivets 31, and are arranged to extend through the opening 22 in spaced relationship to the edges of the member 20 defining that opening. The particular contacts 21 shown in the drawing are of the knife switch type, each one forming the female member of a pair of knife switch contacts, as may readily be seen in Fig. 4.

a recessed flange portion 20a within which the peripheral edge of the sheet-like member 36 may ride. It will be noted that as long as the sheet-like member 36 lies within this recessed flange portion 290, it is prevented from moving radially by the peripheral wall 2% of the recessed flange and is prevented from moving in one direction along the axis of the switch by the radially extending shoulder 20b, forming a part of the recessed flange portion 20a.

, Movement of the member 36 in the opposite direction along the axis of the switch is prevented by a ring 37 which may be secured against the outer lip of the cupshaped member 20 by any suitable means such as the cars 38 which are integral with the cup-shaped member 20 andarebent over the outer edge of the ring 37.

v The movable contacts 35 extend through slits in the supporting member 36 and may be secured firmly in posi tion byany suitable means. It has been found, for example, thatthese contacts may be held firmly in position merely by the tightness of the fit between the contacts and the supporting member 36. The contacts 35 preferably include ears. 35a extending laterally therefrom and engaging one surface of the supporting member for stability. The rotatable contacts are, of course, so located with respect to the stationary contacts 21 that the tips of the rotatable contacts pass between the leaves of the stationarycontacts 21. as the supporting member 36 rotates within the cuprshapedmember 2t).

where knife switch contacts are employed, 'it is, of course, essential that the desired relative positions of two Tcooperable contacts be accurately maintained, particularly in thelradial direction in a rotating switch, since otherwise the male contact of a pair of contacts might fail to pass between the two leaves of the corresponding female cc ntact. It will be noted that when one of the contact supporting elements, for example, the member 36, is prevented'from moving radially with respect to the other contact supporting element 20 by direct engagement of the two'contact supporting elements, there is substantially nopossibility of radial misalignment of the cooperating contacts as long as the proper engagement between the two contact supporting elements is maintained. I It will ,be immediately obvious upon inspection of the ,drawings that thecontact supporting member 36 is very securely held in its proper radial position, as well as in its proper axial position, by the engagement of its peripheral edge with the rugged and simple metallic cup-shaped member 20, which directly supports the stationary contacts. isbelieved to be a substantial improvement over the conventional switch in which the relative osition, 'andi'n particular the relative radial position, of the contact supporting elements is dependent upon proper alignment and "pos tioning of a seriesof interconnecting members such as a drive'shaft, bearings, and various elements of'a framework. The member 20 need not, ofcourse, be literally cup' shaped, even to the extent of the member illustrated. Rather, the term cup-shaped is meant to convey the thought that this member has. portions integral therewith or attached thereto which extend axially from the contact supporting portion 'thereof'to engage the periphery of the other contact supporting member. 7 Each of the cup-shaped members 24) has a pair of cars '40 and'41, which are supported on a framework includling'base'pla'tes 42, screws 43, and spacers 44, The screws ,43extend'the'entire distance between theltwo base plates :42, and the spacers 44 are hollow tubes fitting over the j'sci'ews 43 and extending between adjacent sections of the 'rr'iul'tipl'e switch, The screws 43 pass vthough the openings inthe ears'40 and 41 while the spacers44, which are "toolarge to pass thr'oug'hthe openings in the ears, serve to space the switch sections at a predetermined distance from each other. tightened, holds the entire assembly securely together as a unit.

The screw has a nut 45, which, when have been found to be very economical, and at the same An operating shaft 46 is provided which has a rectangular cross section-in the vicinity of the

switch sections

13, 14 and 15. The shaft 46 extends through circular openings 47 in the cup-shaped members 20 and accordingly is freely rotatable with respect thereto. However, the contact supporting member 36 has a rectangular opening 36:: therein, which snugly engages the shaft 46 whereby rotation of the shaft causes rotation of the member 36 and hence of the rotatable contacts 35 in each of the switch sections. t 7

Since the cup-shaped members are firmly supported by the frame of the switch including the base plates 42 and the screws 43, and since the contact supporting elements 36 are radially positioned by their engagement with the cup-shaped members 30, it is not required that the shaft 46 be supported in bearings. In the interest of greater solidity of the unit the forward end of the shaft 46 is shown supported by a bearing 48 secured to the forward base plate 42, but therearward end of the shaft 46 terminates adjacent the last switch section 15 and is not supported by a bearing.

In the drawings, the rotating contacts 35 are shown connected by a series of coils 50 of dilfering predetermined inductance values. When the switch is rotated, these coils are selectively inserted, by way of example, in the circuits involving the tubes 16, 11, and 12 for changing the inductive characteristics thereof. A switch constructed in accordance with the invention may, however, be applied to many other purposes. For example, two of the movable contacts 35 may be short-circuited or other types of contacts may be employed such that the circuits involved may merely be opened and closed selectively as the switch is operated.

Since one of the contactsupporting members, namely the cup-shaped member 20 in the embodiment described, must extend anappreciable distance axially to engage the periphery of the other contact supporting member 36, it is desirable that the member 20 be of substantial rigidity and strength in order that the radial alignment of these ,two members may be maintained accurately. For this reasonthe member 20 is preferably constructed of a metal ,andis, therefore, electrically conducting.

Each of the'sheets 26 may support only one contact 21 or may be made to support a plurality of contacts as in the illustrated embodiment where two stationary contacts are arranged on each of two of'the sheets 26. It is desirable, however, that the plane of the faces of the contacts 21 supported by the sheets 26 lie tangent to the circular path of the mating contacts 35 at, the point along that path at which the contacts engage. If this is not the case the contacts tend to deteriorate rapidly with use. Also, with this arrangement, the thrust transmitted from the rotatable contacts to the stationary contacts, and hence to the sheets 26, as the switch is rotated, lies along a line parallel to and substantially coincidental withthe plane of the corresponding sheets 26. As a result there is little tendency for this thrust to work the sheets 26 loose from the member 20. V V N This method and construction for mounting the stationary contacts on the electrically conducting member 20 time secure the contacts very accurately and reliably in position, The method and apparatus are particularly jadapted to a switch of the type disclosed. However, the

method and apparatus referred to are not limited to this particular application, but may be employed to advanta ge in many other situations.

Another embodiment of the invention is shown in Figs/8 and 9 in which slots 52 are spaced from the'open- 70.

,ing 22' extending through'the stationary contact'support "20'. Sheets 26' of insulating material extend through the respective slots and are clamped therein by deformation "of the member20 as by punch marks or chisel marks 30'. Each sheet 261 extends part way across theopening 22 and "has a contact ,21' mounted thereon.

This moun ng r an me pa ticu arly de i able i the application of the switch shown in the drawings where it is desired to close contacts which are angularly displaced from each other. It will be noted in Fig. 2 that each of the stationary contacts 21 is arranged on a supporting sheet 26 which is tangent to the circular path of the mating movable contact at a point slightly removed from the point of engagement of the mating contacts. In the embodiment shown in Figs. 8 and 9 the sheets 26' supporting the contacts 21 may be made tangent to the path of the movable contacts exactly at the point of engagement of the mating contacts. The embodiment shown in Figs. 1-7 has on the other hand the advantage of greater rigidity and simplicity.

While particular embodiments of the invention have been shown, it will be understood, of course, that the invention is not limited thereto since many modifications may be made, and it is, therefore, contemplated to cover by the appended claims any such modifications a fall within the true spirit and scope of the invention.

The invention having thus been described, what is claimed and desired to be secured by Letters Patent is:

1. In a construction for mounting an electrical conductor on a conducting plate with said conductor extending through said plate and insulated therefrom, said plate having an opening therethrough and a pair of slots extending through said plate and communicating with said opening; a sheet of insulating material having a pair of edges extending through said slots and fitting snugly therein, said plate being deformed adjacent the edges of said slots to squeeze said sheet therein and thereby to lock said sheet in a fixed position with respect to said plate, an electrical conductor mounted on said sheet in position to extend through said opening in said plate in spaced relationship to the edge of said plate adjacent said opening.

2. The elements of claim 1 in which said slots are aligned.

3. In a construction for mounting an electrical conductor on a conducting plate with said conductor extending through said plate and insulated therefrom, said plate having an opening therethrough and a pair of slots extending through said plate and communicating with said opening; a sheet of insulating material having a pair of edges extending through said slots and fitting snugly therein, said sheet also having a pair of cars extending laterally and outwardly of said edges, said ear forming shoulders engaging said plate beyond the ends of said slots, said plate being deformed adjacent the edges of said slots to queeze said sheet therein and thereby to lock said sheet in a fixed position with respect to said plate, an electrical conductor mounted on said sheet in position to extend through said opening in said plate in spaced relationship to the edge of said plate adjacent said opening.

4. Means for mounting an electrical conductor on a conducting plate with said contacts extending through said plate and insulated therefrom, said means comprising, mean defining an opening in said plate and a pair of slots extending through said plate and communicating with said opening, a sheet of insulating material having a pair of edges extending through said slots and fitting snugly therein, said plate being deformed adjacent the edges of said slots to squeeze said sheet therein and thereby to lock said sheet in place with respect to said snugl th r in sa d he t 159 a n a pair of can xen s la a and t ar y o said e s a can rm sh e en a in s d p e yond t e end of said slots, said plate being deformed adjacent the edges of said slots to squeeze said sheet therein and thereby to lock said sheet in place with respect to said plate, said sheet supporting said electrical conductor in position to extend through said opening in said plate in spaced relationship to the edge of said plate surrounding said opening.

6. An electrically conducting plate having an opening therethrough and a pair of slots extending through said plate and communicating with said opening, a sheet of insulating material having two edges extending through said slots and fitting snugly therein, said plate being deformed adjacent the edges of said slots to squeeze said sheet therein thereby locking said sheet in a fixed position with respect to said plate, and an electrical conductor secured to said sheet and extending through said opening in said plate in spaced relationship to the edges of said plate adjacent said opening.

7. An electrically conducting plate having an opening therethrough and a pair of slot extending through said plate and communicating with said opening, a sheet of insulating material having two edges extending through said slots and fitting snugly therein, said sheet also having a pair of ears extending laterally and outwardly of said edges, said ears forming shoulders engaging said plate beyond the ends of said slots, said plate being deformed adjacent the edges of said slots to squeeze said sheet therein thereby locking said sheet in a fixed position wtih respect to said plate, and an electrical conductor secured to said sheet and extending through said opening in said plate in spaced relationship to the edges of said plate adjacent said opening.

8. The elements of claim 7 in which said slots are aligned.

9. In a multiple contact rotary switch, a contact-supporting metal plate having an opening therethrough and a pair of valigned slots extending through said plate and communicating with said opening, a sheet of insulating material having two edges extending through said slots and fitting snugly therein, said sheet also having a pair of cars extending laterally and outwardly of said edges, said ears forming shoulders engaging said plate beyond the ends of said slots, said plate being deformed adjacent the edges of said slots to squeeze said sheet therein thereby iocking said sheet in a fixed position with respect to said plate, and a switch contact secured to said sheet and extending through said opening in said plate in spaced relationship to the edges of said plate adjacent said opening.

10. The method of mounting an electrical conductor on a conducting plate with said conductor extending through said plate and insulated therefrom which comprises, forming an opening through said plate and a pair of slots communicating with said opening, inserting two edges of an insulating sheet into said slots, deforming said plate adjacent said slots to squeeze said sheet therein and thereby to lock said sheet in a fixed position with respect to said plate, and securing an electrical conductor to said sheet in a position to extend through said opening in said plate in spaced relationship to the edge of said plate adjacent said opening.

11. The method of mounting an electrical conductor on a conducting plate with said conductor extending through said plate and insulated therefrom which comprises, forming an opening through said plate and a pair of aligned slots communicating with said opening, inserting two edges of an insulating sheet into said slots, deforming said plate adjacent said slots to squeeze said sheet therein and thereby to lock said sheet in a fixed position with respect to said plate, and securing an electrical conductor on said sheet in a position to extend through said opening in said plate in spaced relationship to the edge of said plate adjacent said opening.

12. The method of mounting an electrical conductor on a conducting plate with said conductor extending ,said opening.

13. An electrically conducting plate having a slot and another opening extending therethrough, a sheet of insulating material extending through said slot and fitting snugly therein, said, plate being deformed adjacent the edges of said slot to squeeze said sheet therein and thereby to lock said sheet in a fixed position with respect to said plate, and an electrical conductor secured to said sheet and extending through said other opening in said plate in spaced relationship to the edges of said plate adjacent said opening.

14. An electrically conducting plate having a slot and another opening extending therethrough, a sheet of insulating material extending through said slot and fitting snugly therein, said sheet also having a pair of cars extending beyond the confines of said slot and forming shoulders engaging said plate, said plate being deformed adjacent the edges of said slot to squeeze said sheet therein and thereby to lock said sheet in a fixed position .with respect to said plate, and an electrical conductor secured to said sheet and extending through said other opening in said plate in spaced relationship to the edges of said plate adjacent said opening. I

15. An electrically conducting plate having a slot and another opening extending therethrough, said slot and said other opening being spaced apart, a sheet of insulating material extending through said slot and fitting snugly therein, said plate being deformed adjacent the edges of said slot to squeeze said sheet therein and thereby to lock said sheet in a fixed position with respect to said plate, said sheet extending at least partially across said other opening, and an electrical conductor secured to said sheet and extending through said other opening in said plate in spaced relationship to said plate adjacent said opening.

16. In a rotary switch a contact-supporting metal plate having a slot and another opening extending therethrough, a sheet of insulating material extending through said slot and fitting snugly therein, said plate being deformed adjacent the edges of said slot to squeeze said sheet therein and thereby to lock said sheet in a fixed position with respect to said plate, and a switch contact secured to said sheet and extending through said other opening in said plate in spaced relationship to the edges of said plate adjacent said opening.

References Cited in'the file of this patent UNITED STATES PATENTS